Department of Physics and Astronomy, George Mason University


Shobita Satyapal

Dr. Satyapal is a professor in the Department of Physics and Astronomy at George Mason University.  Professor Satyapal received her B.S degree in Physics from Bryn Mawr College and her Ph.D in Physics and Astronomy from the University of Rochester.  She was a postdoctoral researcher at NASA Goddard Space Flight Center.  Prior to joining Mason, she was an instrument scientist for the James Webb Space Telescope at Goddard and Space Telescope Science Institute. Her research centers on understanding the connection between the growth and evolution of supermassive black holes and the host galaxies in which they reside. She utilizes space- and ground-based multi-wavelength data from Chandra, XMM-Newton, WISE, Spitzer, the Very Large Array (VLA), Gemini, the Large Binocular Telescope (LBT), and Keck.  Professor Satyapal is the recipient of numerous awards including the Presidential Early Career Award. Click here for more information about her research.

Dr. Satyapal is currently working on the following projects: intermediate mass black holes, dual supermassive black holes, and supermassive black holes in bulgeless and low mass galaxies. In recent years, she has been enjoying teaching quantum mechanics, statistical mechanics, and waves and radiation.

Melissa Bierschenk

Melissa is a graduate student at George Mason University and holds a B.S. in physics from the University of South Alabama and an M.S. in physics from the University of Minnesota Duluth. While at UMD, Melissa focused on generating Post-Newtonian waveforms of coalescing binary black holes and producing animations of these orbits with its resulting gravitational waves. Her current research involves looking at the MIR spectroscopical properties of 200 AGN from the BASS Survey using the Spitzer telescope. The goal is to understand how the characteristics of the circumnuclear dust change with the accretion properties of the supermassive black hole. Melissa was awarded the Outstanding Graduate Teaching Assistant Award from the UMD Physics & Astronomy Department for the 2019-2020 academic year.

Jenna Cann, black hole graduate student

Jenna Cann

Dr. Jenna Cann got her Ph.D. from George Mason University in 2021, and is an NPP Postdoctoral Fellow at NASA Goddard Space Flight Center. She holds a B.S. in Astronomy, also from GMU. Her work focuses on determining new diagnostics, such as emission lines coming from highly ionized elements called coronal lines, to search for lower mass SMBHs in dwarf galaxies using the photoionization modeling code Cloudy and instruments such as NIRSPEC and NIRES at Keck Observatory.  She is the recipient of several prestigious awards, such as the National Science Foundation Graduate Research Fellowship, Cosmos Club Foundation Cosmos Scholar, and a Sigma Xi Grant-in-Aid of Research.   She is also very active in outreach and conducts tours at the GMU Observatory.

Luis Fernandez

Luis is a Cuban-American born in Miami, Florida who is a non-traditional student. He received his A.S. in Emergency Medical Services at Miami Dade College where he obtained his paramedic’s licence and worked at Palmetto General Hospital for 5 years before going back to school to receive his B.S. in Physics at Florida International University (FIU). Luis is currently a graduate student at George Mason University. Using Radio and X-ray data from observatories such as the Very Large Baseline Array (VLBA) and Swift/Bat, his work examens the feedback of Active Galactic Nuclei (AGN). Currently he is working on a 6 month survey of NGC2992. Luis was awarded the FIU Physics Department’s S-STEM scholarship 2 years consecutively during his undergraduate studies.”

Lara Kamal

Lara is a student at George Mason University and holds a B.S. in Computer Science with an emphasis in Machine Learning. She is currently working on a second degree in Physics also at GMU. Her work focuses on using Machine Learning Algorithms, such as regression, classification, feature reduction, and neural network on Cloudy data, a photoionization modeling code, to determine the mass of the blackhole given a set of emission lines. Lara is a recipient of the Computer Science Outstanding Student Achievement and Academic Achievement in Mathematics Awards.

William Matzko

William is currently a graduate student at George Mason University. As an undergraduate, he double majored in Physics and Astronomy and subsequently earned his B.S. in Physics and Astronomy from George Mason in 2019. His past research experience focused on exoplanets, including simulating time-series data for the EarthFinder mission concept study and validating transiting exoplanets. Currently, his research is focused on understanding the behavior of outflows in galaxies as a function of their merger stage. William is the recipient of several awards, including a travel grant from the Undergraduate Student Travel Fund (USTF) and an outstanding research award from George Mason’s Department of Physics and Astronomy. Beginning in the fall of 2019, he will be one of George Mason’s observatory coordinators.

Jeffrey McKaig

Jeffrey holds a B.S in applied physics and applied mathematics from Christopher Newport University. There his research focused on general relativity and black holes with a concentration on the creation of extragalactic jets. He also researched Compton scattering in the high field regime at Thomas Jefferson National Accelerator Facility in partnership with Old Dominion University. Jeffrey joined GMU to study Active Galactic Nuclei (AGN) from the X-ray perspective and is  currently studying the effect of polar dust on X-ray spectra from AGNs using high resolution simulations. This polar dust was discovered after high resolution interferometry of AGNs in the mid-infrared found a large component extending in the polar direction, which is not expected by the classical unified model of AGNs. Studying this polar component of dust in the X-ray regime could act as a unique probe of the kinematics of the polar gas. These simulations will provide a fundamental benchmark for future high spectral resolution X-ray instruments, such as those onboard XRISM and Athena.

Ryan Pfeifle

Ryan is an NPP Fellow at NASA Goddard who got his Ph.D. from George Mason University in 2022. Utilizing X-ray observatories such as Chandra, XMM-Newton, and NuSTAR, his work focuses on the search for dual AGN in mid-IR preselected late-stage galaxy mergers, characterizing the levels of AGN obscuration in late-stage mergers, as well as understanding AGN triggering and fueling in mergers versus isolated galaxies. Ryan is the recipient of a several awards, including the Sigma Xi Grant-in-Aid of Research (GRIAR) and two competitive International Travel Grants (ITGs) offered by the GMU Associate Provost for Graduate Education. Outreach is also a very important activity for Ryan, and he regularly conducts class and public tours at the GMU observatory.

Michael Reefe

Michael is a senior undergraduate at GMU majoring in physics with a concentration in astrophysics.  He has previously done research on exoplanet validation and characterization with both transit data and radial velocities, as well as a full-scale telescope automation project in Python.  More recently he has transitioned to researching active galactic nuclei (AGNs), searching for coronal line emission in SDSS spectra to examine the interactions between AGNs and their host galaxies.  He is also passionate about teaching and outreach, working as an award-winning learning assistant and president of the student-led group SPECTRUM.

Remington Sexton

Dr. Remington Oliver Sexton received his Ph.D. from the University of California, Riverside in 2020 and is an astronomer working at the United States Naval Observatory (USNO) in Washington D.C.  He received his B.S. in Physics from California Polytechnic State University, Pomona where he studied stellar wind bow shocks using Spitzer Space Telescope imaging of the Carina Nebula.  During graduate school, his research focused on supermassive black hole and host-galaxy co-evolution using spatially-resolved spectroscopy taken from the LRIS instrument at Keck Observatory and imaging from the Hubble Space Telescope.  He developed Bayesian AGN Decomposition Analysis for SDSS Spectra (BADASS), an open-source spectral fitting code used to study ionized gas outflows in AGN host galaxies.  As an astronomer at USNO, he leads the spectroscopic analysis and cataloging of objects that comprise the International Celestial Reference Frame.

Emma Schwartzman

Emma is a graduate student at George Mason University, and holds two bachelor’s degrees – one in Astronomy and one in Physics – from the University of Maryland. She also works at the U.S. Naval Research Laboratory, where her work focuses on the study of galaxy clusters, cluster mergers, and other radio emitters, using ground-based radio interferometry and satellite-based high energy X-ray detectors. She spends the majority of her time performing data analysis for characteristics like source location, size, and spectral characteristics. She primarily works with radio data calibration packages such as CASA and WSCLEAN, as well as X-ray packages such as CIAO. Teaching is also a passion for Emma, and she enjoys her work as a teaching assistant for undergraduate physics and astronomy classes.

Jim Williams

Jim earned his B.S. in Computer Science from the University of Michigan and his M.S. in Computer Science from American University. He served as a naval intelligence officer and then, as a civilian, held several computer science and programming jobs in both private industry and government. Among other  projects, he wrote a compiler for a new computer language, modeled the effects of nuclear weapons, evaluated options for arms control treaties, and designed a Unix computer network. He retired from the Department of Defense in 2013. As a GMU student, he is interested in using X-rays to study active galactic nuclei (AGNs). His current research is on modeling the soft excess in AGNs.

Affiliated Faculty

Jacqueline Fischer

Jackie Fischer is an astrophysicist, formerly in the Radio/Infrared/Optical Sensors Branch of the Remote Sensing Division and led the Infrared – Submillimeter Astrophysics & Techniques Section. She received a B.Sc. degree in physics from the Hebrew University of Jerusalem and a Ph.D. in astronomy from the State University of New York in Stony Brook. She began at NRL as a National Research Council postdoctoral associate and joined the Laboratory in 1988. She has worked on a number of infrared instrumentation projects: she was the technical manager of the HYDICE Hyperspectral Digital Collection Experiment, led the optical specification team for the ASTROCAM astrometric infrared imager for U.S. Naval Observatory, and was a member of the Infrared Space Observatory (ISO) Long Wavelength Spectrometer team. She was appointed as the Herschel Optical System Scientist and as a member of the Herschel Science Team in 2001. Her research interests are in the area of the evolution of galaxies and in particular, on the role that galaxy mergers play in the morphological transformation of galaxies, most recently concerning the structure of the nuclear regions of gas-rich galaxy mergers and in particular on the discovery of massive molecular outflows in gas-rich galaxy mergers and the implications for understanding galaxy feedback in these systems. 

Mario Gliozzi

Dr. Gliozzi’s research activity is focused on the investigation of the physical conditions of matter around black holes based on the analysis and interpretation of X-ray data from different classes of active galactic nuclei (AGN; especially Radio Galaxies, Blazars, Narrow Line Seyfert 1 galaxies, and true type 2 AGN). He is interested in the unification of black hole systems at three different levels:

1) The unification among the different classes of AGN, with particular focus on the radio-loud/radio quiet dichotomy

2) The unification between active and normal galaxies, investigated by studying the X-ray nuclear properties of bulgeless galaxies and Low-power AGN, which may represent the link between powerful AGN and normal galaxies.

3) The unification between AGN and Galactic Black Hole systems, with particular emphasis for the variability properties .

Click here for more information about his research.

Dr. Gliozzi is currently associated with the following research projects: supermassive black holes in bulgeless and low mass galaxies.

Claudio Ricci

Dr. Ricci is an Assistant Professor at the Nucleo de Astronomia of the Universidad Diego Portales, in Santiago, Chile and a long-term visiting professor at the Kavli Institute for Astronomy and Astrophysics at Peking University, in China, and an affiliated faculty at George Mason University, Fairfax, USA, where his the graduate supervisor of several students.

His research is focussed on the structure and evolution of the material around supermassive black holes, combining X-ray spectroscopy with multi-wavelentgth observations. He is part of the core team of the Swift/BAT AGN Spectroscopic Survey (BASS), and of the science team of the hard X-ray NASA mission NuSTAR.

Barry Rothberg

Barry Rothberg obtained his Ph.D. from the University of Hawaii at Manoa in 2004. His Ph.D. dissertation focused on using near-infrared imaging and optical spectroscopy to study the dynamics of merging galaxies in the local Universe. In 2005, he joined Space Telescope Science Institute as a postdoctoral fellow to work on young star clusters in merging galaxies, and in 2007, he was awarded a National Research Council Fellowship at the Naval Research Laboratory where he worked with Dr. Jacqueline Fischer to unravel why some galaxies appeared to have dramatically different masses depending on the wavelength of light used to observe them. In 2011, Dr. Rothberg rejoined Space Telescope to provide support for the slitless grism mode on the the Wide Field Camera 3 aboard the Hubble Telescope. In 2012, he joined the Leibniz Institute for Astrophysics (AIP) as a Senior Postdoctoral Fellow and Support Astronomer for the institute’s share of the Large Binocular Telescope located on Mount Graham in Arizona. Dr. Rothberg continues to work on the properties of merging galaxies in the local Universe and has expanded this work to investigate similar systems at earlier epochs (as far back as 8 Billion lightyears). He is also working with Dr. Pirzkal at Space Telescope Science Institute to apply more robust statistical methods to detecting and measuring the properties of galaxies formed within a few hundred million years after the Big Bang. Dr. Rothberg is currently working to study the properties of black holes in bulgeless and low mass galaxies, as well as merger-triggered accretion onto black holes.

Former Students

Dr. Rachel DudikUnited States Naval Observatory
Dr. William McAlpine
Dr. Nathan SecrestUnited States Naval Observatoryformer National Research Council Fellow

Close Collaborators

Nick AbelUniversity of Cincinnati, Clermont College
Laura BlechaUniversity of Florida
Thomas BohnUniversity of California, Riverside
Torsten BökerSpace Telescope Science Institute
Gabriela CanalizoUniversity of California, Riverside
Anca ConstantinJames Madison University
Sara EllisonUniversity of Victoria
Christina Manzano-KingUniversity of California, Riverside
Claudio RicciUniversidad Diego Portales
Pontificia Universidad Catolica de Chile
Kavli Institute for Astronomy and Astrophysics
Remington SextonUniversity of California, Riverside